Access to Anticancer Drug Trials for Adolescents With Cancer in the United States

BACKGROUND: Adolescents with cancer are generally underrepresented in clinical trials. The extent to which cancer drug clinical trials have become more age inclusive over time is not clear. METHODS: We utilized ClinicalTrials.gov to identify cancer drug trials from 2005 to 2025 in the United States. We categorized trials according to age of eligibility as those for adults only versus those that allowed adults as well as patients <18 years of age. For trials with results reported, we also evaluated whether minor participants enrolled in these trials. RESULTS: We identified 23,756 trials, of which only 14.3% allowed both adults and minors to participate. This proportion did not show a consistent change over the study period, including in a sensitivity analysis focused on trials with histologies particularly relevant to adolescents (germ cell tumors, Hodgkin lymphoma, and sarcomas). The proportion of industry-funded trials was 45% for adult-only trials versus 24% for trials that also allowed minor participants (p < 0.01). Across most years, more than 25% of trials that allowed minors to participate actually enrolled at least one minor participant. Among trials relevant to germ cell tumors, Hodgkin lymphoma, and sarcoma, more than 50% of trials enrolled minors. CONCLUSIONS: A small minority of oncology drug trials in the United States extends the age of eligibility below 18 years of age, and this proportion does not appear to be increasing over time. This extended to histologies, including sarcoma and lymphoma, which may be particularly relevant to adolescent patients. Even when the age of eligibility extends below 18 years of age, most trials did not enroll adolescents, including a significant proportion of those focused on histologies most relevant to adolescent patients.